PWM发脉冲,怎么精确控制发脉冲的个数呢?

2019-07-21 09:01发布

STM32的PWM发送脉冲,周期和脉宽都可调了,但是现在不知道如何精确的控制所发的脉冲个数。
具体要求就是在一段时间内大概50ms内发送5000-1W个脉冲  个数要很精确,误差2个以内可以接受
该怎么控制呢?
1.接上一个外部中断口,在中断中计数
2.用一个定时器 对发脉冲的时间进行控制

各位大侠还有什么好的办法吗?求解啊!
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49条回答
没时间先生1214
1楼-- · 2019-07-22 23:42
回复【9楼】翱翔云端的鸟:
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你好  你的这个程序写好了吗   我尝试按照定时器中断的方式记数  可是最终显示的数值是乱码
翱翔云端的鸟
2楼-- · 2019-07-23 03:46
回复【14楼】没时间先生1214:
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http://www.openedv.com/posts/list/46194.htm
看我的这个帖子
没时间先生1214
3楼-- · 2019-07-23 05:01
回复【15楼】翱翔云端的鸟:
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好哒  谢谢你
qq942266575
4楼-- · 2019-07-23 05:45
 精彩回答 2  元偷偷看……
没时间先生1214
5楼-- · 2019-07-23 07:46


这是主函数


求教楼主   TIM1为主定时器,输出的PWM作为TIM3的时钟,可是我下载到板子上,TIM3完全不起作用,能帮忙看下不,谢谢啦

翱翔云端的鸟
6楼-- · 2019-07-23 12:02
[mw_shl_code=c,true]void TIM4_GPIO_Config(void) { GPIO_InitTypeDef GPIO_InitStructure; /* TIM4 clock enable */ //PCLK1经过2倍频后作为TIM4的时钟源等于72MHz RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); NVIC_Configuration(1); /* GPIOB clock enable */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC, ENABLE); /*GPIOB Configuration: TIM4 channel 1 and 2 as alternate function push-pull */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; // 复用推挽输出 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOB, &GPIO_InitStructure); GPIO_ResetBits(GPIOB,GPIO_Pin_6|GPIO_Pin_7); } void Tim2_Slave_Init(void) { TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_DeInit(TIM2); RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); NVIC_Configuration(8); TIM_TimeBaseStructure.TIM_Period= XBUF[1] - 1; TIM_TimeBaseStructure.TIM_Prescaler= 0; //时钟预分频数 TIM_TimeBaseStructure.TIM_ClockDivision=0; //采样分频 TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;//向上溢出 TIM_TimeBaseInit(TIM2,&TIM_TimeBaseStructure); TIM_SelectInputTrigger(TIM2,TIM_TS_ITR3);//选择TIM2的输入触发源 内部触发3 TIM4 TIM_InternalClockConfig(TIM2); TIM2->SMCR |= 0x0007;//设定从模式控制寄存器,外部时钟模式1 上升沿驱动计数 //TIM_UpdateDisableConfig(TIM4,ENABLE); TIM_ARRPreloadConfig(TIM2, ENABLE); TIM_ClearFlag(TIM2,TIM_FLAG_Update); //清除溢出中断标志 TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE); TIM_Cmd(TIM2,ENABLE);//是否开启时钟(开启后每发送一个脉冲,定时器加一) } void Tim3_Slave_Init(void) { TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_DeInit(TIM3); RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); NVIC_Configuration(9); TIM_TimeBaseStructure.TIM_Period= XBUF[3] - 1; TIM_TimeBaseStructure.TIM_Prescaler= 0; //时钟预分频数 TIM_TimeBaseStructure.TIM_ClockDivision=0; //采样分频 TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;//向上溢出 TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure); TIM_SelectInputTrigger(TIM3,TIM_TS_ITR3);//选择TIM2的输入触发源 内部触发3 TIM4 TIM_InternalClockConfig(TIM3); TIM3->SMCR |= 0x0007;//设定从模式控制寄存器,外部时钟模式1 上升沿驱动计数 //TIM_UpdateDisableConfig(TIM4,ENABLE); TIM_ARRPreloadConfig(TIM3, ENABLE); TIM_ClearFlag(TIM3,TIM_FLAG_Update); //清除溢出中断标志 TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE); TIM_Cmd(TIM3,ENABLE);//是否开启时钟(开启后每发送一个脉冲,定时器加一) } /* * 函数名:TIM4_Mode_Config * 描述 :配置TIM4输出的PWM信号的模式,如周期、极性、占空比 * 输入 :无 * 输出 :无 * 调用 :内部调用 */ void TIM4_PWM_Init(u16 T) { TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure; u16 CCR1_Val = (T+1)/2; u16 CCR2_Val = (T+1)/2; u16 CCR3_Val = (T+1)/2; u16 CCR4_Val = (T+1)/2; /* ----------------------------------------------------------------------- TIM1 Configuration: generate 4 PWM signals with 4 different duty cycles: TIM1CLK = 36 MHz, Prescaler = 0x0, TIM1 counter clock = 36 MHz TIM1 ARR Register = 999 => TIM1 Frequency = TIM1 counter clock/(ARR + 1) TIM1 Frequency = 36 KHz. TIM1 Channel1 duty cycle = (TIM1_CCR1/ TIM1_ARR)* 100 = 50% TIM1 Channel2 duty cycle = (TIM1_CCR2/ TIM1_ARR)* 100 = 50% TIM1 Channel3 duty cycle = (TIM1_CCR3/ TIM1_ARR)* 100 = 50% TIM1 Channel4 duty cycle = (TIM1_CCR4/ TIM1_ARR)* 100 = 50% ----------------------------------------------------------------------- */ /* Time base configuration */ TIM_TimeBaseStructure.TIM_Period = T-1;//T us TIM_TimeBaseStructure.TIM_Prescaler = 72-1; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); TIM4->CR1 &= ((u16)0x03FD);// UDIS enable /* PWM1 Mode configuration: Channel1 */ TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = CCR1_Val; TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; TIM_OC1Init(TIM4, &TIM_OCInitStructure); TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable); /* PWM1 Mode configuration: Channel2 */ TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = CCR2_Val; TIM_OC2Init(TIM4, &TIM_OCInitStructure); TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable); /* TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = CCR3_Val; TIM_OC3Init(TIM4, &TIM_OCInitStructure); TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable); TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = CCR4_Val; TIM_OC4Init(TIM4, &TIM_OCInitStructure); TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);*/ TIM_ARRPreloadConfig(TIM4, ENABLE); TIM_SelectOutputTrigger(TIM4,TIM_TRGOSource_OC1Ref); /* TIM1 enable counter */ TIM_Cmd(TIM4, ENABLE); /* Main Output Enable */ TIM_CtrlPWMOutputs(TIM4, ENABLE); } void TIM4_PWM_START(void) { TIM4_GPIO_Config(); Tim2_Slave_Init(); Tim3_Slave_Init(); TIM4_PWM_Init(XBUF[0]); }[/mw_shl_code]

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